The Hill reports:

Democrats are growing concerned that Robert F. Kennedy Jr.’s profile is rising just as President Biden embarks on a challenging campaign to keep the White House out of Republican control.

Kennedy, an anti-vaccine proponent who launched a primary bid against Biden this spring, is doing unexpectedly well in some polls and receiving increasing media attention as a result. He has also been on a press tour this week that included a Twitter Spaces discussion with Elon Musk and digital town hall with journalist Michael Smerconish.

“Democrats would be foolish to mock or belittle RFK Jr. Every time we make fun of those who hold fringe positions, we lose,” said Michael Ceraso, a Democratic strategist and former campaign aide to Sen. Bernie Sanders (I-Vt.) and Transportation Secretary Pete Buttigieg. “The Democratic Party acting smug never works.”

Kennedy has indeed stirred up some untapped anger within his own party; Democrats have seen him rise to double digits in several recent polls, leading some establishment figures to acknowledge the parts of his message that may be resonating with voters.